1. Field Of Invention
The present invention relates to a fiber optic draw furnace for making optical fiber; and more particularly to insulators for separating a heating element from an outer furnace shell in graphite resistance and inductance furnaces.
2. Discussion of Related Art
Known graphite resistance fiber optic draw furnaces typically have a standard graphite felt insulation insert that may be nonhomogeneous (density variation). The standard graphite felt insulation is very "dirty" (loose graphite particles and graphite fibers). The standard graphite felt is also very susceptible to moisture and oxygen absorption.